ANTI-SENSE RNA FOR CAB TRANSCRIPT TO REDUCE CHLOROPHYLL CONTENT IN PLANTS

摘要

The initial steps in photosynthesis are the conversion of light energy intochemical energy. This conversion is performed by the multisubunit protein-pigment complexes of the thylakoid membranes. Oxygen-evolving photosystemscontain photosystem I (PSI) and photosystem II (PSII), which act in tandem. InPSII, the majority of light-adsorbing chlorophylls are attached to LHCII, thelightharvesting complex associated with this photosystem. LHCII is the mostabundant member of the family of chlorophyll a/b binding (CAB) proteins. Agene encoding a type I chlorophyll a/b binding protein of LHCII (ICABPSII) hasbeen cloned from Brassica napus L. An anti-sense RNA of this gene has beenused to reduce the amount of chlorophyll a/b binding protein and thus reducetheamount of chlorophyll in the resulting transgenic plants. By using "site"specificpromoters the reduction of chlorophyll can be targeted to specific organellesinthe transgenic plant and thus can be used to reduce the green colour at thesesites. Thus it is possible to use the anti-sense RNA of a chlorophyll a/bbindingprotein as a means for degreening, for example fruits, seeds or floral partsintransgenic plants.